Master Record Identification Number (MRID) - A unique cataloging number assigned to an individual pesticide study at the time of its submission to the Agency.
Material Safety Data Sheet (MSDS) - Printed material concerning a hazardous chemical, or Extremely Hazardous Substance, including its physical properties, hazards to personnel, fire and explosion potential, safe handling recommendations, health effects, fire fighting techniques, reactivity, and proper disposal. Originally established for employee safety by OSHA.
Maximum Contaminant Level (MCL) - The maximum level of certain contaminants permitted in drinking water supplied by a public water system as set by EPA under the federal Safe Drinking Water Act.
Maximum Contaminant Level Goal (MCLG) - The maximum level of a
contaminant that is associated with no adverse health effects from drinking
water containing that contaminant over a lifetime. For chemicals believed
to cause cancer, the MCLGs are set at zero. MCLGs are not enforceable,
but are ideal, health-based goals which are set in the National Primary
Drinking Water Standards developed by EPA. MCLs are set as close to MCLGs
as possible, considering costs and technology.
mechanisms of toxicity - The biochemical method by which a chemical reacts in a living organism.
medical waste - All wastes from hospitals, clinics, or other health care facilities ("Red Bag Waste") that contain or have come into contact with diseased tissues or infectious microorganisms. Also referred to as infectious waste which is hazardous waste with infectious characteristics, including: contaminated animal waste, human blood and blood products, pathological waste, and discarded sharps (needles, scalpels, or broken medical instruments).
microbial pesticides - Microorganisms that kill or inhibit pests, including insects or other microorganisms. Sometimes microorganisms get rid of pests simply by growing larger in numbers, using up the pests' food supply, and invading the pests' environment.
microorganisms - Bacteria, yeasts, simple fungi, algae, protozoans, and a number of other organisms that are microscopic in size. Most are beneficial but some produce disease. Others are involved in composting and sewage treatment.
milligrams/liter (mg/l) - A measure of concentration used in the measurement of fluids. Mg/l is the most common way to present a concentration in water and is roughly equivalent to parts per million.
minimization - Measures or techniques that reduce the amount of wastes generated during industrial production processes; this term also is applied to recycling and other efforts to reduce the volume of waste going to landfills. This term is interchangeable with waste reduction and waste minimization.
miticides - Kill mites that feed on plants and animals
mitigation - Measures taken to reduce adverse effects on the environment.
mildews - Thin coatings of powdery fungi that can grow on damp surfaces like bathroom tiles and corners of the bathtub.
molds - Furry fungi that grow on damp surfaces.
molluscicides - Kill snails and slugs
monitoring well - A well used to take water quality samples or to measure ground water levels.
morbidity - Rate of incidence of disease.
mortality - Death rate.
mutagenicity - The property of a chemical that causes the genetic characteristics of an organism to change in such a way that future generations are permanently affected.
National Pollutant Discharge Elimination System (NPDES) - The primary permitting program under the Clean Water Act which regulates all discharges to surface water.
National Response Center (NRC) - The primary communications center operated by the U.S. Coast Guard to receive reports of major chemical and oil spills and other hazardous substances into the environment. The NRC immediately relays reports to a predesignated federal On-Scene Coordinator.
nematicides - Kill nematodes (microscopic, worm-like organisms that feed on plant roots)
neutralization - The chemical process in which the acidic or basic characteristics of a fluid are changed to those of water (pH = 7).
No Observed Adverse Effect Level (NOAEL) or No Observed Effect Level (NOEL) - A level of exposure which does not cause observable harm.
No Observed Adverse Effect Level (NOAEL) - The highest dose in a toxicity stufy which does not result in adverse health effects. Combine with above
non-agricultural sectors - General term which refers to a combination of home/garden and industrial/commercial/governmental sectors.
nonpoint source - Any source of pollution not associated with a distinct discharge point. Includes sources such as rainwater, runoff from agricultural lands, industrial sites, parking lots, and timber operations, as well as escaping gases from pipes and fittings.
non-target organism - Any organism for which the pesticide was not intended to control.
odor threshold - The lowest concentration of a substance in air that can be smelled. Odor thresholds are highly variable because of the differing ability of individuals to detect odors.
Office of General Council
(OGC) - This EPA Office provides legal advice and service to all
organizational elements of EPA, including the Office of Pesticide Programs.
Office of Pesticide Programs (OPP) - This EPA Office registers and regulates pesticides.
On-Scene Coordinator (OSC) - The federal official responsible for the coordination of a hazardous materials response action, as specified in individual Regional Contingency Plans. OSCs are predesignated by EPA for inland areas and by the U.S. Coast Guard for coastal areas. The OSC coordinates all federal containment, removal, and disposal efforts and resources during a pollution incident. The OSC is the point of contact for the coordination of federal efforts with those of the local response community. The OSC has access to extensive federal resources, including the National Strike Force, the Environmental Response Team, and Scientific Support Coordinators. The OSC can be a source of valuable support and information to the community.
OPCumRisk - A computer program developed at ORD's NHEERL to determine relative potency estimates and PoDs for the index chemical.
organically grown - Food, feed crops, and livestock grown within an intentionally-diversified, self-sustaining agro-ecosystem. In practice, farmers build up nutrients in the soil using compost, agricultural wastes, and cover crops instead of synthetically derived fertilizers to increase productivity, rotate crops, weed mechanically, and reduce dramatically their dependence on the entire family of pesticides. Farmers must be certified to characterize crops as organically grown and can only use approved natural and synthetic biochemicals, agents, and materials for three consecutive years prior to harvest. Livestock must be fed a diet that includes grains and forages that have been organically grown and cannot receive hormones, sub-therapeutic antibiotics, or other growth promoters.
other pesticide chemicals - Chemicals registered as pesticides but which are produced and marketed mostly for other purposes, i.e., multi-use chemicals. Notable examples are sulfur, petroleum products (e.g., kerosene, oils and distillates), salt and sulfuric acid.
parts per billion (ppb) - One ppb is comparable to one kernel of corn in a filled, 45-foot silo, 16 feet in diameter.
parts per million (ppm) - One ppm is comparable to one drop of gasoline in a tankful of gas (full-size car).
parts per trillion (ppt) - One ppt is comparable to one drop in a swimming pool covering the area of a football field 43 ft. deep.
pathogen - A bacterial organism typically found in the intestinal tracts of mammals, capable of producing disease.
pathway of exposure - The physical course a pesticide takes from the source to the organism exposed (e.g., through food or drinking water consumption or residential pesticide uses).
permeability - The ease with which water, or other fluid, passes through a substance.
Permissible Exposure Limit (PEL) - Workplace exposure limits for contaminants established by OSHA.
permit - A legal document issued by state and/or federal authorities containing a detailed description of the proposed activity and operating procedures as well as appropriate requirements and regulations. The permitting process includes provisions for public comment.
pesticide - Substances intended to repel, kill, or control any species designated a "pest" including weeds, insects, rodents, fungi, bacteria, or other organisms. The family of pesticides includes herbicides, insecticides, rodenticides, fungicides, and bactericides.
Pesticide Chemical Code
(PC Code) - A six-digit number assigned by OPP
to identify pesticide chemicals. Also called a Shaughnessy code. The PC
Code is often used for searching computer databases because it is short
and easy to enter.
Pesticide Document Management System (PDMS) - The EPA-maintained collection of documents of regulatory significance to pesticides, including submitted studies.
pesticide user expenditures - Dollar value of purchases by persons or businesses applying pesticides, such as farmers, commercial pesticide applicators and homeowners. Reported numbers are nominal values for the years indicated, i.e., not adjusted or indexed for inflation.
pesticide usage - Refers to actual applications of pesticides, generally in terms of quantity applied or units treated.
pH - The measure of acidity or alkalinity of a chemical solution, from 0-14. Anything neutral, for example, has a pH of 7. Acids have a pH less than 7, bases (alkaline) greater than 7.
pheromones - Biochemicals used to disrupt the mating behavior of insects
Point of Departure (PoD) - A dose that can be considered to be in the range of observed responses, without significant extrapolation. A PoD can be a data point or an estimated point that is derived from observed dose-response data. A PoD is used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures.
point source - A stationary location or fixed facility such as an industry or municipality that discharges pollutants into air or surface water through pipes, ditches, lagoons, wells, or stacks; a single identifiable source such as a ship or a mine.
pollution - Any substances in water, soil, or air that degrade the natural quality of the environment, offend the senses of sight, taste, or smell, or cause a health hazard. The usefulness of the natural resource is usually impaired by the presence of pollutants and contaminants.
pollution prevention - Actively identifying equipment, processes, and activities which generate excessive wastes or use toxic chemicals and then making substitutions, alterations, or product improvements. Conserving energy and minimizing wastes are pollution prevention concepts used in manufacturing, sustainable agriculture, recycling, and clean air/clean water technologies.
potable water - Raw or treated water that is considered safe to drink.
private applicator - A category of applicator certification for farmers and/or employees such that they can legally apply restricted use pesticides or supervise others doing so who are not certified.
professional market - Sales of pesticides for application to industrial/commercial/governmental sectors, homes and gardens by certified/commercial applicators.
public comment period - The time allowed for the members of an affected community to express views and concerns regarding an action proposed to be taken by EPA, such as a rulemaking, permit, or Superfund remedy selection.
public water system - Any water system that regularly supplies piped water to the public for consumption, serving at least an average of 25 individuals per day for at least 60 days per year, or has at least 15 service connections.
Publicly Owned Treatment Works (POTW) - A municipal or public service district sewage treatment system.
quality assurance/quality control - A system of procedures, checks, audits, and corrective actions to ensure that all technical, operational, monitoring, and reporting activities are of the highest achievable quality.